Effect of pH on the Transformation of a New Readymix Formulation of the Herbicides Bispyribac Sodium and Metamifop in Water
A laboratory experiment was conducted to investigate the effect of pH on the persistence and the dissipation of the new readymix formulation of bispyribac sodium and metamifop. The experiment was conducted in water of three different pH viz. 4.0, 7.0 and 9.2. The spiking level of both the compounds in water was 1.0 and 2.0 µg/mL. The residues were extracted by a simple, quick and reliable method and quantified by liquid chromatography tandem mass spectrometry (LC–MS/MS). The method was justified based on the recovery study, which was > 85%. The dissipation of both compounds followed first order kinetics. The half-life values ranged between 19.86–36.29 and 9.92–19.69 days for bispyribac sodium and metamifop, respectively. The pH of water has a prominent effect on degradation of both the compounds. The rate of dissipation of both the compounds was highest in water of acidic pH followed by neutral and alkaline pH.
KeywordsBispyribac sodium Metamifop Water pH LC–MS/MS
We are grateful to PI Industries Ltd., Gurgaon, India for financial assistance. The infrastructure facilities provided by the Export testing Laboratory (NABL accredited ISO 17025 certified Laboratory), Department of Ag. Chemicals, Bidhan Chandra KrishiViswavidyalaya, are thankfully acknowledged.
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